Focusing lamp



Sept. 15, 1 925. H. A. DOUGLAS FOCUSING LAIP Originai Filed Jan. 26,1920 Patented Sept. 15, 1925.

UNITED STATES PATENT OFFICE.

HARRY A. DOUGLAS, OF BRONSON, MICHIGAN. i

FOCUSING LAMP.

Original application filed January 26, 1920, Serial No. 354,306. Dividedand this application filed May 23, 1921. Serial No. 471,950.

To all whom it may concern: 7

Be it known that I, HARRY A. DOUGLAS, a citizen of the United States,residing at Bronson, in the county of Branch and State of Michigan, haveinvented a certain new and useful Improvement in Focusing Lamps,

of which the following is a full, clear, concise, and exactdescription.

My invention relates to focusing lamps, being a division of myapplication Serial No. 354,306, filed January 26, 1920.

The invention is of particular service in relation to electricheadlights employed, for example, upon automobiles. In such a lamp thereis a reflector including a reflect-or containing casing, a tubularholder upon and within the casing, a shell within the holder, anincandescent lamp bulb within the shell, the holder being formed with aspring tongue gripping the shell and also being formed with a projectionapart from the tongue while the shell is formed with a longitudinal slotreceiving said projection.

In accordance with another characteristic of the invention there is anadjusting rod in novel assembly with the lamp holding shell.

I will explain my invention more fully by reference to the accompanyingdrawing showing the preferred embodiment thereof and in which Fig. 1 isa view'partially in section and partially in elevation of a por tion ofan automobile headlight structure made in accordance with the invention;Fig. 2 is a view ofparts shown'in Fig. 1 taken flector portions alonebeing shown in section; Fig. 3 is a view in elevation of certain of theparts shown in Fig. 1 looking from beneath these parts as they appearinthe latter figure; Fig. 4 is a viewshowing, in section, the preferredform of easing prior to its assem ly with the threaded adjusting sleevewhich is shown in elevationin this figure; and Fig. 5 illustrates, bythe full lines thereof, the threaded adjusting sleeve inserted as farwithin the casing as possible before the casing is modified to completeits assembly with such sleeve, the assembled positions of these partsbeing indicated by dotted lines.

Like parts are indicated by similar characters of reference throughoutthe different figures.

The concave reflector 1 received in the at right angles thereto, thecasing and re-.

concave casing 2 and is coupled therewithin any suitable way, spaceintervening between the reflector and casing. The reflector in cludes aforwardly extending tubular con-1' tinuation or sleeve 3 in fixedrelation with the balance of the reflector and supported by the casingsince the reflector that holds the sleeve 3 is supported by said casing.This continuation 3 constitutes a holder or mounting that is in the formof a tubular neck. The shell or tubular element 4 is contained withinthe bore of the sleeve 3 and when these two elements are embodied in aheadlight structure the shellis made to be ad justable longitudinally ofthe sleeve. One of the elements 3 or 4, preferably the sleeve, is formedwith circumferentially aligned spring tongues 5 which press transverselyof and upon the shell. -These spring tongues, are desirably produced bymeans of a T-slot whose stem portion 6 extends longitudinally of thesleeve and whose head portion 7 extends circumferentially of the sleeve,the slot portion 6 extending clear to one end of the sleeve in, orderthat the springs may be completely formed to have the desired degree offlexibility. The shell 4 has a recess 8 formed therein, this being thecase if the sleeve is formed with the springs 5, it being understoodthat the invention is not to be limited to the formation of the springsupon the sleeveand the recess in the shell. The element which has thesprings, in this in stance the sleeve, hasa projection 9 apart from thespring which enters the recess 8. The shell has bayonet channels 10 for'receiving the bayonet projections 11 upon a contact carrier. 12. Asillustrated, this contact carrier is in the form of abase of a socalledsingle pole incandescent lamp bulb 13 whose filament has one terminal inconnection witha contact 14 upon the inner end of such base and whoseotherterminal'is connected, with a metallic sheath upon the base whichelectrically engages the metal shell 4 that, in turn, is inelectricalconnection with the sleeve 3 that is j in suitable groundedconnection with one terminal of thesource of current that, is employedfor supplying the lamp bulb.

When the device is employed in a headlight such as is employed inautomobiles, the shell 4 is made free to be adjustable back and forthwithin the [sleeve 3 by making the rein longitudinal adjustment withinthe sleeve. The sleeve also has a. contact carrler held in assembly withthe shell as set forth and claimed in my companion application SerialNo. 8 18, 116, filed December 30, 1920. This contact carrier supports ametallic spring barrel 16 in which there is housed a coil spring 17 thatpresses a contact 18 into engagement with the lamp bulb contact 14:.

This spring barrel has an external continuation 19 formed with a lateralopening 20 that may receive a plug 21, the spring 17 pressing a rearcontact 22 into engagement with this plug as set forth in my aforesaidco-pending application. Current is conveyed to the lamp by means of theplug 21,

tion by being provided with an annular groove 28 into which isextendedthe portion of the caslng 2 thatsurrounds the opening in p thecontacts 18 and 22, and the spring barrel 16 electrically connectingthese contacts.

The rod 23 is coupled with the shell 4 for the purpose of moving thisshell to adjust the focal position of the lamp bulb. This rod ispreferably assembled with the shell by meansof the constructionillustrated, the shell having an aperture 2a in the rearportion of itscylindricalwall which receives a transverse continuation 25 of the rod23; To prevent the rod from being withdrawn laterally from the shell itis provided with a-longitudinal portion26 extend ing forwardly from thetransverse continuation 25 of the rod. In assembling the rod and shellthe rod is first placed at an angle tothe shell to permit of the passageof the longitudinalportion 26 into the aperture 24 wherea-fter the rodis turned to be longitudinal of theshell I and to bring the transversecontinuation 25 into said aperture.

In carrying out another feature'of the invent-ion the rod is threadedabout its rear end and is in threaded engagement with the threaded boreof an adjusting sleeve 27. This sleeve is givena single plane of rotatherear of this casing through which the adjusting sleeve 27 is passed. Forconvenience in turning the sleeve27 the outer and head end of thissleeve is formed with a screwdriver-slot. The annular groove 28 in theadjusting sleeve 27 enables me to dispense with an added part which washitherto employed for confining such a sleeve to a single plane ofrotation; In the process ofassembly the rear portion of the casing 2 isinitially of the shape illustrated in Fig. 4 where it is shown as beingprovided with a rearwardly extending truncated conical portion 29surrounding the opening in this casing with which the'adjusting sleeveis to be assembled. The inner edge of the truncated conical portion 29is first brought into registry with the annular groove 28 as illustratedin Fig. 5, whereafter said conical portion 29 is flattened to bring itinto the general curvature of the casing 2 and to cause it to enter thegroove 28, as illustrated in Figs. 1 and 2.

While I have herein shown and particularly described the preferredembodiment of my invention I do not wish tobe limited to the precisedetails of construction shown as changes may readily be made withoutdeparting from the spirit of my invention,

but having thusdescribed my invention I claim as new and desire tosecure by Letters Patent the following In a focusing lamp structure, areflector, a lamp carrying sleeve mounted for forward and backwardmovements with respect to said reflector whereby focal adjustments ofthe lamp may be effected; and means for imparting forward and backwardmovements to said sleeve including a rod connected at'its forward end tosaid sleeve and extending rearwardly therefrom,

said rod having a substantially right angularly extending portionengaged in an open- 1ng1nsaid sleeve and further having a 10mgitud-inalportion extending forwardly from said right angular portion and engagingthe inner face of the sleeve whereby the rod'is held positively againstdisengagement from the sleeve when the rod is in 'a' rearwardly disposedposition with respect to the sleeve and: whereby the rod is readilydisengageable "from the sleeve by swinging the rod to aline theaforesaid forwardly extending longitudinal portion with the opening insaid sleeve. In witness whereof, I hereunto subscribe 'my. name this28th day ofJune A. D., 1920.

HARRY DOUGLAS.

